Importing "Aiken" format files

The Aiken format is a very simple way of creating multiple choice questions using a clear human-readable format. Here is an example of the format:

What is the correct answer to this question?
A. Is it this one?
B. Maybe this answer?
C. Possibly this one?
D. Must be this one!
ANSWER: D
Which LMS has the most quiz import formats?
A) Moodle
B) ATutor
C) Claroline
D) Blackboard
E) WebCT
F) Ilias
ANSWER: A

The question must be all on one line.

Each answer must start with a single-letter character, followed by a period '.' or a bracket ')', then a space.

The answer line must immediately follow, starting with "ANSWER:" and then giving the appropriate letter.